Overview Part #2

In this two-part blog post i will cover the technical, as well as overall aspects of implementing accessibility into the EventManager Project. And not just any form of accessibility – the Game has earned the AA+ Certification from Access For All (their highest certification grade conform to WCAG 2.0).

Go here for the first blog post on accessibility. This second part will cover all the technically nitty-gritty, blood and tears that went into implementing accessibility for this project. :)

Some Resources First

Throughout my research and while developing the accessiblity implementation for EventManager i’ve collected useful resources on the web which i’m glad i can share with you via my delicious. There are notes for all the links available that will tell you what type of information you will find behind the click.

Accessibility Introduction

If you haven’t worked with accessiblity in Flash or Flex yet, here’s a short introduction on how it all works.

Flash has it’s own package responsible for all the accessibility features. This package is situated under flash.accessibility.*

Within this package (as of this writing) you will find three classes:

• Accessibility
• AccessibilityProperties
• AccessibilityImplementation

The Accessibility class is a static class that allows you to do three important things. From that class you can check if the user is actually using a screenreader and if it is available or not (Accessibility.active). It also allows you to make sure that all accessibility properties are updated if you change any of their values (Accessibility.updateProperties()). The third and in my opinion most important bit of this class is the capability to manually submit an Event to the MSAA API (Accessibility.sendEvent()).

The AccessibilityProperties class is the place where you define the properties, such as name, description and shortcut that are being presented to accessibility aids. You can also set some properties that control the behaviour of your object towards screenreaders. AcessibilityProperties can be attached to any type of DisplayObject.

The AccessibilityImplementation class, is a bit of a special one. It is the base class in Flash that allows for the implementation of accessibility. This class you will never really use directly, since Adobe advices us not to instantiate it but instead extends AccImpl (which again extends from AccessibilityImplementation) in order to create our own implementation for any custom component we might create. The AccImpl class exists in two versions, one for flash and one for flex.

More Than a Million Words

Instead of boring you any further with details and long paragraphs of information, i figured it’s easier to understand how this all works by actually showing you. Enjoy the videos, if the quality is a bit low and you would like them to be sharper, make sure to head over to the vimeo site itself to download the original videos directly from there.

A Basic Example

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A Basic AccessibilityImplementation Example

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The Final EventManager Accessibility Approach

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Preamble

The greater part of last year i was heads-down-busy developing the EventManager Game which i had the pleasure to build at Liip for Postfinance. EventManager is an educational but fun game, that approaches topics such as budgeting, financing and investing in a modern way (read: not boring you to death).

Today i want to talk to you about the new iteration of the game that we just released a couple of weeks ago. What is new you ask? How about: Accessibility! And not just any form of accessibility – the Game has earned the AA+ Certification from Access For All (their highest certification grade conform to WCAG 2.0).

Overview Part #1

In this two-part blog post i will cover the technical, as well as overall aspects of this endeavour. This first part will cover a brief history of accessibility within the Flash Platform and its current state and hopefully useful insight if you are considering to add accessibility to one of your projects.

Accessibility History in Flash

Thanks to Adobe (and of course Macromedia back then), the Flash Platform has been sporting accessibility features since Macromedia released Flash MX back in 2002. For those that remember, this used to be Flash Player in version 6 and just introduced the Vector Drawing API (ahh, nostalgia.. but i digress).

Over the years obviously the feature set has vastly improved and Adobe (rightly so) can be proud of the level of accessibility that the Platform has today, since it allows you to:

• Create your own tab order
• Set alternative text (naming & description text)
• Set shortcuts
• Set element focus (also visually if needed)
• Communicate statuses to screenreaders.

As you see, there is really not much to wish for left here. In fact, if you use the Flex Framework, all these functionalities and features are just a step away from you. But that’s not all, Adobe has made it quite simple to build your own components within the flex framework, that can with little work, implement the accessibility layer. If that wasn’t enough you even have the capability to manually trigger an event to tell attached screenreaders that something has changed within your application.

For us developers, this means that we have the tools and capabilities to fully fullfill the guidelines proposed by WCAG 2.0.

Dark Side of the Accessible Moon

One of the “limitations” when it comes to the Flash Platform and accessibility, is that it’s only available for the Windows Platform.

There have been many voices that critisized Adobe for “only” implementing the Microsoft Active Accessibility (MSAA) API, yet to this day it seems that it is the only documented and standardized API out there. Also it is to be said, that the most popular and wide used screenreader applications have their home only on the Windows Platform.

Misconceptions & Half Truths

Question: So, since the Flash Platform supports accessibility so well, how come there are only a few accessible flash sites out there?

This question is usually met with one of the following answers:

ANSWER: Costs for implementation too high

There is no denying that implementing accessibility into a flash application is a high cost investment, if you do not already have a developer with prior such knowledge.

This has multiple reasons. Depending on your application it will require an entire different approach than just the straight forward making «Your-Standard-RIA App» or «Form-based GUI App» accessible. Which obviously, unless you have done it before will require tinkering, information gathering, experimenting and lots of testing. Hence, it will take time and thereby cost money.

ANSWER: Too difficult & lack of documentation

I have good and bad news. The good news is if you are considering making your RIA accessible, rejoice! Most of the information / documentation on accessibility for the Flash Platform is actually directly aimed at the Flex Framework and at RIA development.

And here is the bad news: if you want to make something completely custom – like a game – accessbile, make sure you have enough time at your hands, you will need it :). But since you are reading this, hopefully i’ll be able to provide you with enough information to ease your pain :).

The main problem lies not in the fact that implementing is difficult or complicated, it’s the fact that real in-depth documentation is either missing, hard to come by and that examples usually only cover little ground. So the difficulty of implementing accessbility really only comes from the fact that you will have to invest lots of time into testing and debugging.

ANSWER: No time / No money within the project

This really is a convergence of the previous two points. Lack of knowledge and the possible cost of implementation, compared to the percentage of users who actually will benefit from that step, leads often – and here we have to be honest to ourselves – to the quick dismissal of accessibility within projects.

ANSWER: What? Flash is accessible?

Yes genius, have you missed the memo? In fact a few years back when i took Macromedia’s Certified Flash Developer exams there was already a huge part dedicated to accessibility within the exam. Go read up, right now!

Adobe followed in Macromedia’s footsteps and continued to improve accessibility, updating the accessibility features once more in their latest Flex 4.0 Framework and implementing their entire accessibility layer into the freshly released AIR 2.0.

The Challenge

Coming back to our topic at hand, for EventManager i was confronted with a game that had many requirements.

The game’s flow for example, does not allow a regular tab order, it just wouldn’t work. There were also many interactions that would take place without any prior user action and those had to inform the player obviously about what is happening.

Depending on where you were in the game or what you wanted to do, the keyboard had to apply a different layout/scheme that is tailored to the task at hand. For example, when you are on the eventgrounds, you need to be able to place/manipulate constructions, which obviously has an entire different control scheme than for example having to bid on an artist in the auction part of the game.

To make the matter worse, the game has a strong mix of pure flash elements and flex components. Oh, and everything had to be multilingual of course :)

Finding a Solution

Keyboard accessibility was pretty clear from the start. We needed a class that allows us to set a specified keyboard layout/scheme to be active when we needed it.

For user-interactions, it was generally agreed that a context-menu would make most sense and thereby should be used for building constructions and general interaction with the eventgrounds in the game.

When it came to implementing screenreader accessibility the concept had to change a couple times, obviously here the lack of knowledge was a problem and forced me to try out various things until finally finding a working and valiable solution.

At this point i would like to extend my most grateful thanks to Adobe’s Accessibility Evangelist (congrats on the new position!) Matt May , he was of incredible help and was able to give me just the right hints, that helped me resolve some key issues that were plaguing me during my quest for accessibility.

The Final Solution

The final solution can be broken down into three essential parts:

• A global Keyboard Controller that allows applying different control schemes at will.
• A single class from which we can communicate with a screenreader to manipulate its focus, send text to be read via speech synthesizer or displayed on a braille device.
• Last but not least a custom context menu component, that allows us to display a menu of possible actions the user can undertake depending on the situation.

I’ll be covering all the technical details and attempted approaches in the second blog post: Flash & the Quest for Accessibility – Part #2.

The Information Hunt

I’ve invested countless hours in information gathering and hunting down resources concering accessibility and possible ways of implementation so that most screenreaders are supported.

Sadly, as it turns out, supporting all available Windows screenreaders seems to be impossible (see these tests). Thereby i concentrated on JAWS and ZoomText since these two applications seem to be the most widely used, when it comes to assistive technologies.

The resources gathered throughout the project that were useful are publicly available via my delicious account. They have notes as to what information was useful and/or if parts of the information was incorrect or not valid anymore.

Conclusion

All in all, getting the chance to implement accessibility in such a big flex application was an incredibly rewarding experience in multiple aspects.

Getting the chance to actually implement accessibility was a great, allbeit, at times nerve-wracking experience that gave me new and invaluable knowledge.

The most rewarding aspect of the entire project though, to me personally, was to receive the excited feedback from our targeted end-users audience. A big thanks also here to Access4All, the entire team at LIIP and everyone else involved in this big effort and of course to Postfinance for giving us this great opportunity.

Feel free to leave comments or get in touch with me if you have any further questions about flash, flex or accessibility.

If you use AIR Applications under Windows and all of sudden those apps can’t connect to the internet anymore, make sure that your Internet Explorer is not “Working Offline”. You can check in the Menu of Internet Explorer under Tools -> Work Offline. If it has a checkmark, remove it and your apps should be working fine again.

I’m really suprised that the Windows Version of AIR apparently retrieves it’s Network Capabitilies via Internet Explorer and that this behaviour is in no way documented anywhere. Hopefully Adobe will changes this or atleast make sure that people now about this.

You can grab the Project Sourcecode here.

If you want to watch the video in the size it was intended for, go to the Tutorial Page on the Project Homepage.

The first installment is covering “Installing & Setting up the TweetrProxy” and you can watch it in it’s intended size by following this link.

Installing & Setting up the TweetrProxy from Sandro on Vimeo.

On the Tweetr-Front i’ve already released v1.0 beta 2 which adds a couple fixes. Here a short update:

• AS: changed serviceHost call from getter to internal variable _serviceHost [minor]
• AS: added serviceHost to OAuth Class since same crossdomain problem applies [major]
• PROXY: added OAuth Authorization support [major]
• ASDOC: Update Documentations, also added which Methods require Authentication [minor]

As usual you can download the new version from the Project Homepage.

But sometimes you don’t want to go through the process of adding a Loader and EventListeners so you can load that external css file just for a bit of fancy html text. Sometimes it would be nice to just compile that thing into your swf and pretty much be done with it.

Well lucky enough we can embed files in classes with the embed tag.

Example:

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// Embed your stylesheet with the octet-stream mime-type
[Embed(source="assets/stylesheet.css", mimeType="application/octet-stream")]
private var stylesCSS:Class;
 
public function createStyleSheetObject():StyleSheet
{
    // create a new StyleSheet instance
    var styleSheet:StyleSheet = new StyleSheet();
    // create a instance of the styles as ByteArray
    var byteArray:ByteArray = new stylesCSS() as ByteArray;
    // read the content
    var stylesString:String = byteArray.readUTFBytes(byteArray.length);
    // parse the string by the stylesheet and done!
    styleSheet.parseCSS(stylesString);
    return styleSheet;
}

Of course this would be the proper way, if you want to save some lines you could also do the following:

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// Embed your stylesheet with the octet-stream mime-type
[Embed(source="assets/stylesheet.css", mimeType="application/octet-stream")]
private var stylesCSS:Class;
 
public function createStyleSheetObject():StyleSheet
{
    // create a new StyleSheet instance
    var styleSheet:StyleSheet = new StyleSheet();
    styleSheet.parseCSS(new stylesCSS().toString());
    return styleSheet;
}

There you go, your StyleSheet is ready to be used.

UPDATE:

Vikas had a very good question concering how to embed multiple stylesheets with this method. I figured i would give another example on how to achieve this very simply. In order to not have to deal with multiple files to embed, you could just join all the styles for a stylesheet into one file, like this:

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/* StyleSheet 1 */
 
.myStyle
{
	fontFamily: Arial;
	fontWeight: bold;
}
/* @eos */
 
/* StyleSheet 2 */
 
.myStyle
{
	fontFamily: Georgia;
	fontWeight: normal;
}
/* @eos */

As you see there is a comment block called /* @eos */ that represent the “end of stylesheet”. This we will split in our code as follows:

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// Embed your stylesheet with the octet-stream mime-type
[Embed(source="assets/stylesheet.css", mimeType="application/octet-stream")]
private var stylesCSS:Class;
 
public function createStyleSheets():Array
{
    // create a instance of the styles as ByteArray
    var byteArray:ByteArray = new stylesCSS() as ByteArray;
 
    // read the content
    var stylesString:String = byteArray.readUTFBytes(byteArray.length);
 
    // split the string with your delimiter. in this case "/* @eos */"
    var matches:Array = stylesString.split("/* @eos */");
 
    // loop through the generated array and create the stylesheets and push
    // them to a new array that will contain those stylesheet objects
    var styleSheets:Array = [];
    var n:int = matches.length;
    for (var i:int = 0; i < n; i++)
    {
        var styleSheet:StyleSheet = new StyleSheet();
        styleSheet.parseCSS(matches[i]);
        styleSheets.push(styleSheet);
    }
 
    // return the StyleSheet Array
    return styleSheets;
}

And voila, you got an array of stylesheets that you can apply to wherever you want. Hope that helps!

• Open a new Tab
• Enter about:config in the addressbar
• Void the warranty! (You’ll see what i mean)
• Look for extensions.checkCompatibility
• Set the value to false
• You may or may not have to restart Firefox

And that’s it! Keep in mind not to blame Firefox for incompatible Extensions that do not work now ;) To reverse those Settings you can always do the same steps and just set the value back to true.

So obviously i was a little upset seeing that Flex Builder 3 doesn’t feature either a Task Management or even a modern Versioning System. But don’t fret!

Since Flex Builder 3 is Eclipse based you can easily install subclipse to get svn running. To find out how to install subclipse to your builder just follow this generic installation guide over at the subclipse website.

For the Tasks i tried a couple things before i started scavenging the net. But then i found the TODO/FIXME extension, a task plugin done by Dirk Eismann for Flex Builder 2 that still works even with Flex Builder 3.

And there you go. Two helpful features added to your beloved Flex Builder. Hope this helps someone out there.